Website Tracking Checker

Free · no sign-up

Page URL (optional)

Used only to spot a first-party tag manager served from your own domain.

Page HTML source

Open the page, press Ctrl+U (Cmd+Option+U on Mac) or type view-source: before the URL, then select all and copy.

Checked in your browser. Nothing you paste is uploaded.

Results appear here

Tag managers, analytics, ad pixels and consent tools found in the source, with their IDs.

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Overview

What Is the Website Tracking Checker?

A website tracking checker scans a page for the code that analytics and advertising platforms use to measure visits and conversions. It answers practical questions: is GA4 installed, which Google Tag Manager container is on the page, is the Meta Pixel present, and is old Universal Analytics code still lying around. This checker reads the HTML source you paste, so it shows what is installed directly on the page. Tags that a tag manager loads later in the browser do not appear in the source, and the result tells you when that may be the case.

Key Functionalities

Detects tag managers, analytics tags, ad pixels, behaviour analytics and consent tools in HTML source.
Shows the IDs it finds, such as GTM, GA4 and Google Ads IDs.
Flags retired Universal Analytics code and first-party Tag Manager setups.

Who Is This For?

Marketers checking that campaign pixels are installed
Analysts auditing a site before or after a migration
Developers confirming which tags are hard-coded in templates

What it does

What the Website Tracking Checker gives you

Key Features

Tag managers
Finds Google Tag Manager containers and their GTM IDs, and notes when the container is served from your own domain.
Analytics
Detects the Google tag for GA4, retired Universal Analytics code, Segment, HubSpot, Matomo and Plausible.
Advertising pixels
Detects Google Ads, Meta Pixel, LinkedIn Insight Tag, TikTok Pixel, Microsoft UET, X, Pinterest and Snap tags.
Consent tools
Spots Google Consent Mode defaults and common consent platforms such as Cookiebot, OneTrust and Usercentrics.

Benefits

Private by design
Detection runs in your browser. The HTML you paste is never uploaded.
Catch duplicate tags
See when the same ID appears twice, a common cause of double-counted conversions.
Clean up old code
Find leftover Universal Analytics snippets and pixels for platforms you no longer use.

Real-Life Applications

Before a campaign launch
Confirm the ad platform's pixel is on the landing page before you spend.
After a site migration
Check that tracking survived a redesign or platform change.
Competitor research
See which analytics and ad platforms a competitor's public page loads.

How it works

How to Use the Website Tracking Checker

01
Open the page source
Open the page in your browser and press Ctrl+U (Cmd+Option+U on Mac), or type view-source: before the URL.
02
Copy everything
Select all of the source and copy it.
03
Paste and check
Paste it into the checker, add the page URL if you want first-party tagging detected, and click Check tracking.
04
Confirm in the browser
If a tag manager is installed, use Google Tag Assistant to see the tags it fires as the page loads.

FAQ

Frequently Asked Questions

Why paste the source instead of entering a URL?

Reading another site's page from your browser is blocked for security reasons, and this site does not fetch pages on your behalf. Pasting the source lets the check run entirely in your browser.

Why are some tags missing?

Tags configured inside Google Tag Manager, or added only after a visitor accepts cookies, load in the browser and are not in the HTML source. Use Google Tag Assistant to see tags as they fire.

Is anything I paste stored?

No. Detection runs in your browser and nothing is sent to Multivariate.

What does a first-party tag manager mean?

If the Google Tag Manager script is served from your own domain rather than googletagmanager.com, the site likely uses a server-side or first-party tagging setup.

Can it check whether tags fire correctly?

No. It shows what is installed in the source. To check firing and the data sent, use Google Tag Assistant or each platform's own debugging tools.